1. Technical Field
The present invention relates to a light wavelength detector and contact probes using it. More particularly, the invention relates to contact probes such as a scanning probe and a touch trigger probe for coordinate measuring machines.
2. Related Art
Contact probes for coordinate measuring machines have various types, examples of which are an optical detection type in which a posture of a stylus (movable body) is triangulated, another optical detection type in which a movement length of a movable body is detected on a linear scale, and a type in which a posture of a movable body is detected by detecting an amount of strain by disposing an electrostrictive element in an elastic deformation portion of the movable body. Such a stylus posture detector is disposed as an internal sensor inside the housing of a contact probe. For example, light beams emitted from three LEDs are caused to shine on three reflection surfaces of a reflection mirror which is disposed in a top portion of a stylus and resulting three reflection light beams are detected by a photosensor. When the posture of the stylus is varied, the reflection mirror is displaced, whereby the reflection directions of the three respective reflection light beams are varied and their incident positions on the photosensor are shifted accordingly. A posture variation of the stylus is calculated by detecting shift lengths of the respective reflection light beams. Such a stylus posture optical detection method using light beams emitted from LEDs is disclosed in Patent document 1, for example.